Development of Fluorescent Probes for the Determination of Binding Sites on Albumin: Studies of the Relationship of the Molecular Structure, Association Constant and Specificity

Abstract

The human serum albumin, HSA, is a major protein constituent from blood plasma. Among its functions, it highlights its performance in the transport of drugs. This property is particularly relevant in the context pharmacokinetic, since the HSA-drug interaction may interfere with the bioavailability of the drug in the body, affecting its therapeutic action. Therefore, evaluate the interaction between drugs or other exogenous substances and the HSA is of great importance for the understanding of the pharmacokinetic characteristics. HSA has two major binding sites called site I and site II. The determination of the drug binding sites on HSA is done by the use of fluorescent probes that bind to these sites. Recent studies in our research group, as well as a critical survey of the results presented in the literature, revealed inconsistencies in the application of site I dansyl probes, which has lead to misinterpretations of the substances studied characteristics with respect to the albumin binding site. Therefore, this project aims to study and synthesis of new dansyl amino acids that can help to elucidate the binding sites of drugs in HSA. Specifically, it is intended to characterize the interaction parameters including binding constants (spectroscopic and calorimetric techniques), characterization of the sites by competitive studies, interaction studies by induced circular dichroism, molecular dynamics studies, among others. As models will use the dansyl amino acids dansilados dansylamide, dansylarginine and dansylisine to the site I and dansylproline, dansylnorleucine and dansylserine to site II. With the results with these compounds will be proposed structural changes that lead to new dansyl compounds with greater specificity to the site I of HSA.